Consolidated Statements Of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016
Consolidated Statements Of Comprehensive Income [Abstract]
Net sales	$ 74,561	$ 69,516	$ 147,415	$ 135,458
Cost of sales	57,001	52,349	109,729	102,243
Gross profit	17,560	17,167	37,686	33,215
Selling and general expenses	5,418	5,614	11,178	11,441
Intangibles amortization	5		372	568
Operating profit	12,137	11,553	26,136	21,206
Other income	980	188	1,930	371
Earnings from continuing operations before provision for income taxes	13,117	11,741	28,066	21,577
Provision for income taxes from continuing operations	4,176	3,805	9,152	7,131
Earnings from continuing operations	8,941	7,936	18,914	14,446
Earnings from discontinued operations, net of tax	771	338	8,953	1,039
Net earnings	$ 9,712	$ 8,274	$ 27,867	$ 15,485
Weighted average shares outstanding:
Basic and diluted	6,990	6,970	6,985	6,967
Earnings per share, basic and diluted:
From continuing operations	$ 1.28	$ 1.14	$ 2.71	$ 2.07
From discontinued operations	0.11	0.05	1.28	0.15
Net earnings per share	$ 1.39	$ 1.19	$ 3.99	$ 2.22
Other comprehensive income, net of tax:
Unrealized gain (loss) on available-for-sale securities	$ (5)	$ 13	$ 23	$ 18
Comprehensive income	$ 9,707	$ 8,287	$ 27,890	$ 15,503
Cash dividends declared and paid per common share	$ 0.00	$ 0.00	$ 5.50	$ 5.05